Solid state particulate metal oxide infrared emitter apparatus and method of use thereof

ABSTRACT

The invention comprises an infrared source and method of use thereof comprising the steps of: (1) providing a solid state source, comprising: a film of oxide particles comprising an average particle size of less than ten micrometers, gaps between the oxide particles comprising an average gap width of less than ten micrometers, and a heating element embedded in the solid state source; (2) applying a pulsed current to the heating element to heat the heating element; and (3) heating the film of oxide particles to at least seven hundred degrees using thermal conduction from the heating element resultant in the film of oxide particles emitting infrared light in a range of 1.1 to 20 micrometers, where the infrared source operates continuously with heating and cooling of the oxide particles through a differential of at least 200° C. occurs at least five and less than thirty times per second.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/678,038 filed Aug. 15, 2017.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates generally to a light source.

Discussion of the Prior Art

Patents related to the current invention are summarized here.

Proton Beam Therapy System

-   P. Nordal, et. al., “Infrared Emitter and Methods for Fabricating    the Same”, U.S. Pat. No. 6,031,970 (Feb. 29, 2000) describe an    infrared radiation source, comprising a thin, electrically    conducting film adapted to emitted infrared radiation when heated.-   I. Romanov, et. al., “High-Temperature Nanocomposite Emitting Film,    Method for Fabricating the Same and its Application”, World Patent    application no. WO 2014/168977 A1 (Oct. 16, 2014) describe a    thin-film radiative structure comprising molybdenum, silicon,    carbon, and oxygen.

Problem

There exists in the art of light sources a need for an accurate,precise, miniaturized, and rapidly switchable infrared light source.

SUMMARY OF THE INVENTION

The invention comprises a mid-infrared light source apparatus and methodof use thereof.

DESCRIPTION OF THE FIGURES

A more complete understanding of the present invention is derived byreferring to the detailed description and claims when considered inconnection with the Figures, wherein like reference numbers refer tosimilar items throughout the Figures.

FIG. 1 illustrates novel elements of a solid state emitter;

FIG. 2 illustrates a top view of an infrared source;

FIG. 3 illustrates a side view of the infrared source;

FIG. 4A and FIG. 4B illustrates a reflector, back reflector, orreflective layer embedded in the infrared source;

FIG. 5A illustrates metal oxide nanoparticles in an infrared source andFIG. 5B illustrates the metal oxide nanoparticles coupled to aswitchable heating element;

FIG. 6 illustrates a low mass semi-transparent, electrically conductivemetal oxide light emitter coupled to the reflective layer in the solidstate emitter;

FIG. 7A and FIG. 7B illustrate a first exemplary manufacturing processof the solid state emitter;

FIG. 8 illustrates a manufacturing process of the embedded reflectivelayer of the solid state emitter;

FIG. 9A and FIG. 9B illustrated adding a metal oxide nanoparticle layerto the solid state emitter;

FIG. 10 illustrates emission of the solid state emitter; and

FIG. 11 illustrates light emission of the solid state emitter as afunction of current, temperature, and time.

Elements and steps in the figures are illustrated for simplicity andclarity and have not necessarily been rendered according to anyparticular sequence. For example, steps that are performed concurrentlyor in different order are illustrated in the figures to help improveunderstanding of embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention comprises an infrared source and method of use thereofcomprising the steps of: (1) providing a solid state source, comprising:a film of oxide particles comprising an average particle size of lessthan ten micrometers, gaps between the oxide particles comprising anaverage gap width of less than ten micrometers, and a heating elementembedded in the solid state source; (2) applying an alternating/pulsedcurrent to the heating element to heat the heating element; and (3)heating the film of oxide particles to at least seven hundred degreesusing thermal conduction from the heating element resultant in the filmof oxide particles emitting infrared light in a range of 1.1 to 20micrometers, where the infrared source operates continuously withheating and cooling of the oxide particles through a differential of atleast 200° C. occurs at least five and less than thirty times persecond.

Light Source

Referring now to FIG. 1, a solid state source 100 is described.Generally, the solid state source 100 comprises a light emittingelement, which emits photons in the infrared region of theelectromagnetic spectrum.

In one embodiment, still referring to FIG. 1, the light emitting elementemits photons/energy as a blackbody radiator, such as in themid-infrared region of the electromagnetic spectrum between two and sixmicrometers and more preferably with a peak emission intensity in arange of four to six micrometers.

Still referring to FIG. 1, the solid state source 100 comprises one ormore of:

-   -   a mid-infrared/infrared light source;    -   an infrared emitter, such as a metal oxide, a ceramic, and/or a        cermet;    -   a current and/or heat driven infrared emitter 110;    -   a high surface area-to-volume ratio 120 of the infrared emitter        110, such as greater than 200, 500, 1000, or 2000 to 1;    -   an electrically conductive emitting layer 130;    -   an alternating and/or pulsed current functionality 140;    -   a low mass heated element 150;    -   a semi-transparent emitter 160;    -   a thermally conductive driven emitting layer 170;    -   an embedded reflective layer 180; and    -   a nanoparticle, a metal oxide and/or a ceramic, emitter 190.

Each of the infrared emitter 110, the high surface area-to-volume ratio120 of the infrared emitter 110, the electrically conductive emittinglayer 130, the pulsed current functionality 140, the low mass heatedelement 150, the semi-transparent emitter 160, the thermally conductivedriven emitting layer 170, the embedded reflective layer 180, and thenanoparticle emitter 190 are further described, infra.

Herein, for clarity of presentation, a metal oxide and/or asemi-conducting metal oxide is used as an example of the infraredemitter 110; however, optionally a ceramic is used in place of the metaloxide and/or an inorganic, non-metallic, optionally crystalline oxide,nitride or carbide material is used in place of the metal oxide.

Elements of the solid state source 100, described herein, functiontogether, but are optionally arranged in many permutations andcombinations. For clarity of presentation and without loss ofgenerality, multiple examples are provided herein to illustratefunctionality of individual elements of the solid state source 100 andto illustrate useful substructures and combinations of individualelements of the solid state source 100.

Example I

Referring now to FIG. 2, a first example of the solid state source 100is illustrated, from a top or emission end view. Generally, the solidstate source 100 comprises: a case 210 or housing and the infraredemitter 110. The infrared emitter 110 emits light/photons/energy in theinfrared range of 1.1 to 20 μm and/or the mid-infrared range of 2.5 to20 μm. More preferably, the infrared emitter 110 emits photons havingwavelengths longer than 2, 2.5, 3, 3.5, or 4 μm and/or has a peakintensity of emission in a range of 2 to 6 μm or 4 to 6 μm. The infraredemitter 110 as described herein has a longer wavelength of peakemission, of 4 to 5 μm, compared to competing molybdenum and/or carbonbased emitters. Further, the infrared emitter 110, as described herein,emits at least 10 or 20 percent more light in the range of 3.9 to 8 μmthan the competing molybdenum and/or carbon based emitters. Asillustrated, the infrared emitter 110 is circular. However, the infraredemitter 110 is optionally of any shape such as triangular, square,rectangular, and/or polygonal as the infrared emitter shape isoptionally and preferably formed in a mask/etching step, as furtherdescribed infra. As illustrated, the infrared emitter 110 is embeddedinto the solid state source 100 and is optionally and preferably coatedwith at least a capping layer 350, as further described infra. However,the infrared emitter 110 optionally comprises an outermost surface ofthe solid state source 100.

Still referring to FIG. 2, an electrical system 230 of the solid statesource 100 is illustrated. Generally, the electrical system 230comprises a first contact 238 and a second contact 239 on oppositesides, such as radial sides, of the infrared emitter 110. A first wire231 and a second wire 232 carry current to/from the first contact 238and the second contact 239, respectively. The current passes from thefirst contact 238, through the infrared emitter 110, and into the secondcontact 239 or vise-versa, which raises the temperature of the infraredemitter to 1000° C. or within 25, 50, 100, or 200° C. of 1000° C. basedupon the applied current while using less than 1 Watt. Stated anotherway, the infrared emitter comprises the electrically conductive emittinglayer 130 and/or is the electrically conductive emitting layer 130. Thecurrent heats the infrared emitter 110, which results in radiativerelaxation of the infrared emitter 110 and/or the emission of photons,in the infrared region of the electromagnetic spectrum, from theinfrared emitter 110. The current is optionally direct current, such asgenerated using less than 0.5, 1, 2, or 5 Watts. However, preferably,the current is an alternating, pulsed, and/or duty cycle appliedcurrent, such as faster than 1 Hz operating at less than 0.1, 0.5, 1, 2,or 5 Watts. The pulsed current functionality 140, provides pulsed heat,by way of electrical resistance, to the infrared emitter 110, whichcoupled with: (1) the low thermal mass of the heated element 150 or theinfrared emitter 110, allowing for rapid heating and cooling; (2) thehigh surface area-to-volume ratio 120 of the infrared emitter 110,allowing for rapid cooling; and/or (3) insulating layers, describedinfra, sandwiching the thin infrared emitter 110, which reduces/preventscurrent driven thermal heating of adjacent layers, yields pulsedintensity of the solid state source 100 at the pulsed current frequency,as further described infra. Applied currents are optionally andpreferably greater than 100, 200, 300, or 400 mW and less than 700, 800,1000, or 1200 mW. Optional pairs of a third wire 233 and a fourth wire234 and/or a fifth wire 235 and a sixth wire 236 are used to distributeelectrons across the first contact 238 and/or the second contact 239, anthus across the infrared emitter 110. The distributed current results indistributed heating of the infrared emitter 110 and thus a more uniformprofile of intensity as a function of wavelength versus x/y-position ofthe infrared emitter 110. Similarly, the optional curved shape of thefirst contact 238 and/or the second contact 239, to provide a moreuniform distance to a chosen shape of the infrared emitter 110,functions to smooth the current across the infrared emitter 110,distribute resulting heat on the infrared emitter 110, and/or to yield amore uniform emission profile of the infrared emitter 110 as a functionof x/y-position. For clarity of presentation, components of theelectrical system 230 are generally not illustrated in subsequentexamples, though the electrical system is optionally and preferablyconnected to the infrared emitter 110 in all illustrated embodiments.

Example II

Referring now to FIG. 3, a second example of the solid state source 100is illustrated, from a side view. Emissions from the infrared emitter110 include surface emitted photons 221, which emit from a surface ofthe infrared emitter 110 and body emitted photons 222, which emit froman internal volume of the infrared emitter 110, transmit through aninternal pathlength in the infrared emitter 110, and pass through anouter perimeter of the infrared emitter 110. Herein, transmittance ofthe infrared emitter 110 is at least 10, 20, 30, 40, 50, 60, 70, 80, or90 percent, where transmittance is the percent of photons emitted fromthe internal volume of the infrared emitter 110 than reach an outerperimeter of the infrared emitter 110.

Still referring to FIG. 3, the infrared emitter 110 is encapsulated,such as by a set of encapsulation layers and/or dielectric films. Asillustrated, the set of encapsulation layers comprise: a first layer330, a second layer 340, and a capping layer 350. Optionally andpreferably, the first layer 330 and the second layer each comprise adielectric film and/or a silicon nitride film. Optionally andpreferably: (1) the first layer 330 comprises a low pressure chemicalvapor deposition (LP-CVD) layer deposited at a relatively highertemperature of 800° C.±100, 200, or 300° C. and (2) the second layer 340comprises a plasma enhanced chemical vapor deposition (PCVD) layerdeposited at a relatively lower temperature of 350° C.±50, 100, or 150°C. The first layer 330 and the second layer 340 optionally andpreferably substantially contact opposite sides of the infrared emitter110, which is optionally and preferably an elongated deposited film. Thefirst layer 330, intermediate infrared emitter 110, and second layer340, referred to herein as the infrared emitter assembly, rotate withthe solid state source 100. The first layer 340 is optionally anymechanical enhancement film used to support the infrared emitter 110 andis preferably a first silicon nitride layer substantially comprisingSiN_(x) after annealing, where x is a positive integer. The second layer340 is optionally any material protecting the infrared emitter 110 fromoxidation and is preferably a second silicon nitride layer substantiallycomprising SiN_(y) after annealing, where y is a positive integer thatis optionally greater or less than x. The optional capping layer 350 isany material protecting the outer surfaces of the infrared emitter 110,such as ends and edges of the film, from the environment and/or fromoxidation and is preferably a third silicon nitride layer. Generally,any number and/or type of encapsulating layers are used in the solidstate source 100 at any number of positions and/or locations.

Example III

Still referring to FIG. 3, for clarity of presentation and without lossof generality, a first composite construction 300 of the solid statesource 100 is illustrated in a third example. As illustrated, the solidstate source 100 comprises: (1) a substrate 310, such as a siliconsubstrate; (2) an oxidized layer 320, such as a silicon dioxide layer;(3) the infrared emitter assembly with the first layer 330 substantiallycovering and substantially contacting an outer face of the oxidizedlayer 320; and (4) the optional capping layer 350 covering at least theedges of the exposed infrared emitter 110 and preferably covering thefront surface of the infrared emitter 110.

Example IV

Referring still to FIG. 3, for clarity of presentation and without lossof generality, a fourth example of the solid state source 100 isillustrated where the solid state source 100 comprises a thermal massreduction. As illustrated, an aperture 390 is formed in the substrate310 to reduce the thermal mass of the solid state source 100. Asillustrated, the aperture extends into the substrate 390 of the solidstate probe 100 and optionally and preferably extends to a deepestpenetration 392 part way through the oxidized layer 320. Thecross-section shape of the aperture 390 is of any shape and optionallyand preferably matches a cross-section shape of the infrared emitter110. The aperture 390, preferably, does not extend into the infraredemitter 110. The aperture 390 is optionally formed by any means, such aspredrilling or drilling, but is preferably etched.

Example V

Referring now to FIG. 4A, a fifth example of the solid state source 100is illustrated, where the solid state source 100 comprises an embeddedreflector or reflective layer 360. Generally, the embedded reflectivelayer 360 comprises a mirror, a mirror layer, a reflective layer, aphoton reflective layer, a metalized layer, a diffusely reflectivelayer, and/or an index of refraction mismatched layer. The embeddedreflective layer 360 comprises a layer or partial layer anywhere in thesolid state source 100, such as physically contacting the infraredemitter 110 or removed by 1, 2, 3, or more layers from the infraredemitter 110. Generally, photons emit from the solid state source 100 ona front side of the infrared emitter 110 and the embedded reflectivelayer 360 is positioned on a back side of the infrared emitter 110. Theembedded reflective layer 360 is optionally formed as an focusing ordefocusing element through control of shape of the embedded reflectivelayer 360. As illustrated, the embedded reflective layer 360 comprises adeposited film layer substantially contacting and covering the back sideof the infrared emitter 110. Optionally, an intervening layer, such as asilicon nitride layer is positioned between the embedded reflectivelayer 360 and the infrared emitter 110. As illustrated, a preliminaryetching step, described infra, etched away a portion of the first layer330 to form a cavity substantially filled by the embedded reflectivelayer 360. Preferably, the first layer 330 is the first silicon nitridelayer, SiN_(x), formed by low pressure chemical vapor deposition,deposited at 800° C.±50° C. onto a silicon dioxide layer. Referring nowto FIG. 4B, an optional layer, a secondary lower sandwiching layer 335,such as a silicon nitride layer, is illustrated in theSiN_(x):ZnO:SiN_(y) sandwich assembly.

Still referring to FIG. 4A, the infrared emitter 110 is illustratedemitting three classes of photons. The three classes of photonscomprise: (1) the surface emitted photons 221, which emit from thesurface of the infrared emitter 110; (2) the body emitted photons 222,which emit from an internal volume of the infrared emitter 110 andtransmit through an internal pathlength in the infrared emitter 110; and(3) reflected photons 223, which comprise photons from the first and/orsecond class that back reflect off of the embedded reflective layer 360and subsequently pass through the outer perimeter of the infraredemitter 110. The inventor notes that traditional infrared emitters arenot transparent, which results in a lower observed photon intensity asonly the first class of emitters, the surface emitters, are observed.Optionally and preferably, the transmittance of the infrared emitter 110is high enough to yield at least a 10, 20, 30, or 50 percent increase inphotons emerging from the front side of the infrared emitter 110 whenthe embedded reflective layer 360 is positioned in the solid statesource 100.

Example VI

Referring now to FIG. 5A and FIG. 5B, a sixth example of the solid statesource 100 is illustrated using a nanoparticle metal oxide layer 500.Generally, the nanoparticle metal oxide layer 500 comprises metal oxidenanoparticles 510 of any geometry. Optionally and preferably, the metaloxide nanoparticles 510 comprises nanocrystals, nanoplatelets, and/ornanotubes, also referred to herein as nanorods. Generally, the metaloxide nanoparticles 510 comprise nanoparticles with a mean minimumcross-section distance of less than 1000, 100, 50, 25, 10, 5, or 2 μmand greater than 1 nm. The nanoparticle metal oxide layer 500 optionallycontains gaps 520, between the metal oxide nanoparticles 510. The gapscomprise a mean average distance between the metal oxide nanoparticles510 that is less than 1000, 100, 50, 25, 10, 5, or 2 nm and greater than0.1 nm and is preferably less than the mean minimum cross-sectiondistance of the metal oxide nanoparticles 510 and/or within 10, 20 50,100, or 200 percent of the mean minimum cross-section distance of themetal oxide nanoparticles 510. Preferred metal oxide nanoparticlescomprise: oxides of zinc, silicon, molybdenum, and carbon with optionaldopants and/or impurities of any element, such as chemical forms ofaluminum, bromine, boron, fluorine, chromium, hafnium, titanium, andsilicon. The nanoparticle metal oxide layer 500 is optionally used asthe infrared emitter 110.

Example VII

Referring still to FIG. 5A and FIG. 5B, a seventh example of the solidstate source 100 is described. In a first case, the gaps 520 compriseair and in a second case, the gaps 520 are substantially filled with adeposited gap filling material, such as greater than 70, 80, 90, or 95percent filled on an emission surface of the nanoparticle metal oxidelayer 500. Generally, resultant from thermal heating, one of the metaloxide nanoparticles 510 emits a photon, which travels through one ormore of the gaps 520 and optionally travels through one or more of theremaining metal oxide nanoparticles 510, through a process oftransmission and/or scattering, until the photon emits from thenanoparticle metal oxide layer 500, such as toward a reflector orreflective layer or within a solid angle of emission on a front surfaceof the nanoparticle metal oxide layer 500. Naturally, a multitude ofphotons emit from metal oxide nanoparticles 510 and follow individualpaths within the nanoparticle metal oxide layer 500 prior to emission.Optionally, in a first gap filled case of the nanoparticle metal oxidelayer 500, the deposited gap filling material comprises an index ofrefraction that increases a net emission of photons from thenanoparticle metal oxide layer 500 compared to a second case of thenanoparticle metal oxide layer 500 comprising air in the gaps 520. Apreferred index of refraction of the deposited gap filling material isin the range of 1.45 to 3.0 and/or within 0.5 and/or 1.0 of an index ofrefraction of the metal oxide nanoparticles 510. For instance, in thecase of the metal oxide nanoparticles 510 comprising substantially zincoxide with an index of refraction of 1.8, the index of refraction of thedeposited gap filling material is optionally 1.8±0.5 and/or 1.8±1.0. Thegap filling material is optionally mixed with, deposited, and/orsputtered onto/into the metal oxide, optionally under a partial vacuum,such as into a powder form of the metal oxide nanoparticles 510 andsubsequently baked, annealed, and/or treated with ultrasound to set thenanoparticle metal oxide layer 500 and/or drive off air from the volumeof the nanoparticle metal oxide layer 500.

Example VIII

Referring now to FIG. 5B, an eighth example of the solid state source100 is described. As illustrated, the solid state source 100 comprises aheating element 560 and the nanoparticle oxide layer 500. In use,resultant from heating using the heating element 560, the metal oxidenanoparticles 510 of the nanoparticle oxide layer 500 emit photons, suchas a fourth class of photons 224 emitted from the surface of thenanoparticle oxide layer 500 and/or a fifth class of photons 225 emittedfrom an internal volume of the nanoparticle oxide layer 500, which aresubsequently transmitted/diffusely reflected through the metal oxidenanoparticles 510 and/or the gaps 520 until emission from a frontemission surface of the nanoparticle oxide layer 500. A sixth class ofphotons 226 comprises the fourth class of photons 224 and/or the fifthclass of photons 225 that reflect off of the embedded reflective layer360 and are subsequently emitted from the solid state source, asillustrated in FIG. 6.

Still referring to FIG. 5B, the nanoparticle oxide layer 500 isoptionally heated by the heating element 560 and/or heated viaconductive heat resultant from heating of the infrared emitter 110 basedon a current flow through the infrared emitter 110, as described supra.

Still referring to FIG. 5B, in practice the solid state source 100comprises one or both of the nanoparticle oxide layer 500 and theinfrared emitter 110. As illustrated, the nanoparticle oxide layer 500and heater element 560 are supported on the support element 570.Optionally, the nanoparticle oxide layer 500 and or the heater element560 are supported by and/or in contact with any one or more of: asupport element 570, which is optionally the substrate 310, silicon, thefirst layer 320, silicon dioxide, a mechanical support layer, anoxidation reduction layer, the second layer 330, the lower siliconnitride layer, the third layer 340, the upper silicon nitride layer, asilicon nitride deposit, the capping layer 350, the infrared emitter100, and/or an intervening layer between the nanoparticle oxide layer500 and the infrared emitter 110.

Example IX

Referring now to FIG. 6, a ninth example of the solid state source 100is illustrated. In this example, multiple subsections, described supra,of the solid state source 100 are integrated. Particularly, a basesection 610 is integrated with an infrared emitter section 620 and azinc oxide nanoparticle section 630. In this example, the base section610 comprises: a silicon substrate, a silicon oxide layer, and a thermalmass reduction section. The infrared emitter section 620 comprises: azinc oxide emitter coupled to a back reflector, such as the first layer330:infrared emitter 110:second layer 340 sandwich assembly, optionallywith a secondary lower sandwiching layer 335 sandwiched between a firstnitride layer and the zinc oxide layer couple to the back reflector. Thezinc oxide nanoparticle section comprises: zinc oxide nanoparticles in afilm comprising gaps, optionally filled, between the zinc oxidenanoparticles. Generally, any of the layers are deposited films and anyof the sections are layers of deposited films. The layers and/orsections are optionally configured in any combination and/or permutationto emit light from the solid state source 100 along a first illuminationface and optionally to emit light from two or more illumination faces,such as a left face and a right face.

Manufacturing

Herein, four exemplary manufacturing process are illustrated. Steps inthe first, second, third, and/or fourth manufacturing example areoptionally implemented in many orders, with omission of one or moresteps or layers, and/or with inclusion of one or more additional stepsor layers. It should be appreciated that the three manufacturingexamples are presented to facilitate a description of the solid statesource 100 without loss of generality. Further, descriptions of elementsand/or steps in the four exemplary manufacturing examples are optionallyimplemented in the above described solid state source 100 examples andvise-versa.

Example I

Referring now to FIG. 7A and FIG. 7B a first manufacturing example isillustrated. As illustrated, for clarity of presentation and withoutloss of generality, an example of the solid state source 100 is builtupward from a base substrate to a top capping layer. For clarity ofrelating individual layers of a set of layers, such as the oxidizedlayer 320, the first layer 330, the infrared emitter 110, the secondlayer 340, and the capping layer 350, to steps in a first manufacturingprocedure using particular chemical layers and/or processes, theparticular chemical layers are illustrated side-by-side with the set ofgeneric layers. The first manufacturing procedure 700 comprises one ormore of the steps of:

-   -   providing a silicon, Si, wafer 705;    -   thermally oxidizing 710 and/or etching the silicon wafer to form        a silicon dioxide, SiO₂, layer;    -   depositing a first silicon nitride, SiN or SiN_(m), 715 layer to        the silicon dioxide layer, such as through use of low pressure        chemical vapor deposition, to form a mechanical support layer        with optional oxidation protection properties;    -   depositing a zinc oxide, ZnO, 720 layer to the first silicon        nitride layer, such as through a spray pyrolysis or plasma vapor        deposition process, with an optional and preferred subsequent        step of thermal annealing to form a zinc oxide material,        Zn_(x)O_(y), (ZnO Zn_(x)O_(y)), where y is less than x, such as        at a ratio, y:x, of less than 1:2, 1:5, 1:9, 1:10, 1:10, 1:100,        and/or 1:1000;    -   depositing a second silicon nitride, SiN or SiN_(n), layer 725        and/or a low-stress nitride layer to the zinc oxide material,        such as through use of a second low pressure chemical vapor        deposition step, to form an oxidation protection surface on the        zinc oxide, where m=n or preferably m≠n;    -   patterning 730 the zinc oxide layer, such as via etching away: a        portion of the second silicon nitride layer and a portion of the        zinc oxide layer;    -   adding a capping layer 735, such as another silicon nitride        layer formed using low pressure chemical vapor deposition;    -   adding connectors 740 to the zinc oxide, which is an infrared        emitter layer, through forming a set of holes/channels to the        zinc oxide and adding/depositing a metal connector material in        the set of holes/channels along with a wired connection of the        formed metal connectors to a power supply and/or a main        controller, which controls subsequent applied current to/through        the zinc oxide; and    -   reducing a thermal mass 745 of the resulting solid state source        100, such as through removal of a portion of the silicon wafer        and/or the silicon dioxide layer proximate the zinc oxide        infrared emitter section.

Example II

Referring now to FIG. 8 a second manufacturing example is illustrated.In this example, an embedded reflecting element is added to the solidstate source 100. The second manufacturing procedure 800 comprises oneor more of the steps of:

-   -   the above described step of depositing a first silicon nitride,        SiN or SiN_(m), 715 layer to a starting layer, such as the        silicon dioxide layer, through use of a deposition process, such        as the low pressure chemical vapor deposition process, to form a        mechanical support layer with optional oxidation protection        properties;    -   a step of etching a mirror cavity 810 into the first silicon        nitride layer; and    -   depositing a reflective material 820 into the mirror cavity.

Instances of use of the second manufacturing procedure 800 comprise:adding a back reflecting surface behind, below as illustrated in FIG. 6,the thermal irradiator or infrared emitter 110; adding a mirroredelement behind the zinc oxide layer; adding a reflective surface behindthe nanoparticle metal oxide layer 500; and/or forming a light directingreflective optic.

Example III

Referring now to FIG. 9A a third manufacturing example is illustrated.In this example, the nanoparticle metal oxide layer 500 is added to thesolid state source 100. The third manufacturing procedure 900 comprisesone or more of the steps of:

-   -   installing a heat source 910, such as a heating element 912,        onto a portion of the solid state source 100, such as a nitride        layer;    -   depositing a layer of the nanoparticle metal oxide 920, such as        nanoparticles of zinc oxide, onto the heating element 912,        optionally after adding the intervening secondary lower        sandwiching layer 335; and    -   optionally embedding an optical coupling medium 930 into a        formed or forming layer of nanoparticles of zinc oxide.

As described, supra, the source of heat/energy leading to the emissionof mid-infrared photons from the zinc oxide nanoparticles is optionallyconductive heat transfer from the zinc oxide layer heated with theapplied current, such as through the embedded electrical connectorsinto/onto the zinc oxide film.

Example IV

Referring now to FIG. 9B a fourth manufacturing example is illustrated.In this example, the connectors are added to the metal oxide layerand/or the zinc oxide layer. The fourth manufacturing procedure 800comprises one or more of the steps of:

-   -   adding metal connectors 745, such as a first metal contact        238/first connector to the first wire 231 and/or a second metal        contactor 239/second connector to the second wire 232, where the        step of adding the metal connectors 745 optionally comprises the        steps of drilling/etching/forming a hole/groove/channel into the        solid state source 100 at least to the zinc oxide film and        filling the resultant cavity, such as through deposition, with a        conducting element, such as a metal, comprising a section of        each of the metal contacts.

The connectors are optionally connected to the zinc oxide and/or theinfrared emitter 110 through deposition of a connector, etching asurface to form an electrical connection, and/or through other processesknown in the art.

Energy Delivery/Emission/Use

Referring now to FIGS. 10 and 11, emission of emission elements, theinfrared emitter 110, the film of zinc oxide, the metal oxidenanoparticles 510, the ceramic, and/or the zinc oxide nanoparticles, inthe solid state source 100 as a function of applied current, heat,and/or energy is described.

Referring still to FIG. 10, emission profiles 1000 of the solid statesource 100 and/or the emission elements of the solid state source 100 isillustrated at a first temperature 1010 and at a second temperature1020. Generally, the peak emission intensity of the solid state source100 is in the range of 4 to 5 μm as described, supra, and the emissionintensity is a function of applied voltage/current to the infraredemitter 110 or the conductive thermal transfer of heat to the metaloxide nanoparticles 510. The resultant infrared source of photonscouples well with a lead salt detector, such as a lead selenidedetector, a PbSe detector, a lead sulfide detector, and/or a PbSdetector.

Referring again to FIG. 11, controlled temperature cycling 1100 of thesolid state source 100 is illustrated. As illustrated, an alternating,pulsed, and/or duty cycle current profile 1110 is applied to theinfrared emitter 110. As illustrated, the pulsed current profile 1110has a period of 100 milliseconds; however, the period is optionallygreater than 1, 2, 5, 10, 50, or 100 milliseconds and/or less than 50,100, 200, or 500 milliseconds. As the current is increased, thetemperature profile 1120 of the infrared emitter 110 increases and whenthe current is stopped, switched off, and/or substantially reduced, thetemperature profile 1120 of the infrared emitter 110 decreases, both theincrease and the decrease in temperature lagging the current profile.

Referring again to FIG. 10 and still referring to FIG. 11, the inventornotes that the temperature profile 1120 of the infrared emitter 110periodically cycles with a period of the applied pulsed current, thatthe lag is short, such as less than 1, 5, 10, 20, or 50 milliseconds,and that the change in temperature from a baseline to a peak in eachperiod of the temperature profile 1120 is sufficient to drive theresultant emission of the infrared emitter 110 up and down in a periodicfashion due to the heat transfer design of the solid state source 100.More particularly, by the applied current heating the infrared emitter110 directly, a time lag of an increase in temperature from, a baselineto 95 percent of maximum, of the infrared emitter 110 is less than 1, 5,10, or 20 percent of the period of the applied pulsed current. Further,the heat dispersion/thickness and non-electrically conducting propertiesof the first layer 330 and second layer 340, such as the first nitridelayer and the second nitride layer, in the sandwich structure about theinfrared emitter 110 described supra, keep the current isolated in theinfrared emitter 110 and facilitate rapid heat dispersion, respectively.Further, a thin thickness of the infrared emitter 110, such as less than2, 5, 10, or 20 μm, facilitates heat dissipation from the infraredemitter 110 once the applied current is cycled down in the currentprofile 1110. Further, the film shape of the infrared emitter 110, withthe current passing along/through a width and along/through alongitudinal axis/face of the film, where the width and/or length of thefilm is at least 2, 5, 10, 20, 50, 100, 500, or 1000 times the height ofthe deposited film, where the deposited film is less than 0.3, 0.4, 0.5,0.75, or 1 μm, and/or where a ratio of the length times width of thefilm-to-the height of the film, [(l×w)/h] exceeds 500, 1000, 1500, 2000,and/or 4000-to-1 (4000:1), which also functions to rapidly disperse heatfrom the infrared emitter 110 once the applied current is reduced and/orcycled downward. For instance, the width of the infrared emitter 110 ispreferably 1 or 2 millimeters wide and the thickness of the infraredemitter is preferably less than 0.5, 1, 1.5, 2, 3, 5, or 10 μm thick.Further, the rapid dissipation of heat energy from the infrared emitter110 coupled with micrometer film thicknesses, such as less than 1, 2, 5,10, 20, or 50 μm, of intervening layers, such as the second layer 340,allows a rapid heat increase and subsequent rapid temperature decreaseof the nanoparticle metal oxide layer 500, and metal oxide nanoparticles510 therein, as the pulsed current rises and falls, respectively, whichyields an alternating increase and decrease of the emission from themetal oxide nanoparticles from a baseline to peak exceeding 50, 100,1000, or 5000:1. Still further, the heating element 912, which is a filmoptionally and preferably approximating the dimensions of the infraredemitter 110 film and/or the nanoparticle metal oxide layer 500, has alarge surface area-to-volume ratio of greater than 100 or 500:1 allowingrapid heating, rapid heat transfer to the metal oxide nanoparticles 510,and rapid heat dissipation, which again allows for pulsing and/orcycling resultant light emission from the solid state source 100. Stillfurther, the clipping of the infrared emitter 110, such as in thepatterning step 730 reduces the volume of the infrared emitter 110 to adesired source window without resultant heating of the infrared emitter110 behind opaque, blocking, or thermally insulating elements of thesolid state emitter 100, such as outside a light emission aperture.Still further, the step of reducing thermal mass 745 reduces the thermalmass of the solid state emitter 100, which facilitates temperaturecycling and emission cycling of components thereof and maintaining apeak intensity to baseline difference as the solid state emitter 110 isused continuously. Still further, the low mass of the infrared emitter110 and/or the heating element 912 facilitates use of a low powersource, such as a source operating at less than 2, 1, 0.75, and/or 0.5Watts, allowing battery and portable operation. Hence, the design of thesolid state emitter 100 as a whole: (1) exceeds functionality of theindividual elements of the solid state emitter 100; (2) comprisingmanufacturing steps result in a novel and unanticipated solid statesource providing a new and useful functionality of a portable, small,readily manufactured, low power, and/or a periodically varying or on/offcapability; and (3) comprising particular described combinations andorientations of components of the solid state emitter 100 result in anovel emission profile as a function of both wavelength and time.

Herein, the solid state source 100 is optionally used in any applicationrequiring an infrared source, such as in a mid-infrared spectrometer, amid-infrared meter, as a portion of an electronic device, and/or as aportion of a light-emitting diode.

Herein, zinc oxide is optionally replaced with any conductor, such assilver, aluminum, platinum, and/or copper or with an oxide of any of theconductors, such as silver oxide, aluminum oxide, black platinum, and/orcopper oxide. Further, zinc oxide is optionally replaced with a ceramicmaterial. More generally, zinc oxide, which is an inorganic compound anda wide-bandgap semiconductor of the II-VI semiconductor group isoptionally replaced with any wide-bandgap semiconductor of the II-VIgroup. Preferably, material substituted for the zinc oxide comprises theinventor noted benefits of zinc oxide: a semi-transparent material asdefined supra, high electron mobility, a wide band gap, and a strongluminescence at room temperature.

Herein, any particular element or particular chemical composite, such asSi, SiO₂, ZnO, SiN, is optionally substantially, such as greater than70, 80, 90, 95, or 99%, the particular element or the particularchemical deposit, where impurities and/or doped material make up a massbalance of the particular element of the particular chemical composite.

Still yet another embodiment includes any combination and/or permutationof any of the elements described herein.

The main controller, a localized communication apparatus, and/or asystem for communication of information optionally comprises one or moresubsystems stored on a client. The client is a computing platformconfigured to act as a client device or other computing device, such asa computer, personal computer, a digital media device, and/or a personaldigital assistant. The client comprises a processor that is optionallycoupled to one or more internal or external input device, such as amouse, a keyboard, a display device, a voice recognition system, amotion recognition system, or the like. The processor is alsocommunicatively coupled to an output device, such as a display screen ordata link to display or send data and/or processed information,respectively. In one embodiment, the communication apparatus is theprocessor. In another embodiment, the communication apparatus is a setof instructions stored in memory that is carried out by the processor.

The client includes a computer-readable storage medium, such as memory.The memory includes, but is not limited to, an electronic, optical,magnetic, or another storage or transmission data storage medium capableof coupling to a processor, such as a processor in communication with atouch-sensitive input device linked to computer-readable instructions.Other examples of suitable media include, for example, a flash drive, aCD-ROM, read only memory (ROM), random access memory (RAM), anapplication-specific integrated circuit (ASIC), a DVD, magnetic disk, anoptical disk, and/or a memory chip. The processor executes a set ofcomputer-executable program code instructions stored in the memory. Theinstructions may comprise code from any computer-programming language,including, for example, C originally of Bell Laboratories, C++, C#,Visual Basic® (Microsoft, Redmond, Wash.), Matlab® (MathWorks, Natick,Mass.), Java® (Oracle Corporation, Redwood City, Calif.), andJavaScript® (Oracle Corporation, Redwood City, Calif.).

Herein, any number, such as 1, 2, 3, 4, 5, is optionally more than thenumber, less than the number, or within 1, 2, 5, 10, 20, or 50 percentof the number.

Herein, an element and/or object is optionally manually and/ormechanically moved, such as along a guiding element, with a motor,and/or under control of the main controller.

The particular implementations shown and described are illustrative ofthe invention and its best mode and are not intended to otherwise limitthe scope of the present invention in any way. Indeed, for the sake ofbrevity, conventional manufacturing, connection, preparation, and otherfunctional aspects of the system may not be described in detail.Furthermore, the connecting lines shown in the various figures areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. Many alternative or additionalfunctional relationships or physical connections may be present in apractical system.

In the foregoing description, the invention has been described withreference to specific exemplary embodiments; however, it will beappreciated that various modifications and changes may be made withoutdeparting from the scope of the present invention as set forth herein.The description and figures are to be regarded in an illustrativemanner, rather than a restrictive one and all such modifications areintended to be included within the scope of the present invention.Accordingly, the scope of the invention should be determined by thegeneric embodiments described herein and their legal equivalents ratherthan by merely the specific examples described above. For example, thesteps recited in any method or process embodiment may be executed in anyorder and are not limited to the explicit order presented in thespecific examples. Additionally, the components and/or elements recitedin any apparatus embodiment may be assembled or otherwise operationallyconfigured in a variety of permutations to produce substantially thesame result as the present invention and are accordingly not limited tothe specific configuration recited in the specific examples.

Benefits, other advantages and solutions to problems have been describedabove with regard to particular embodiments; however, any benefit,advantage, solution to problems or any element that may cause anyparticular benefit, advantage or solution to occur or to become morepronounced are not to be construed as critical, required or essentialfeatures or components.

As used herein, the terms “comprises”, “comprising”, or any variationthereof, are intended to reference a non-exclusive inclusion, such thata process, method, article, composition or apparatus that comprises alist of elements does not include only those elements recited, but mayalso include other elements not expressly listed or inherent to suchprocess, method, article, composition or apparatus. Other combinationsand/or modifications of the above-described structures, arrangements,applications, proportions, elements, materials or components used in thepractice of the present invention, in addition to those not specificallyrecited, may be varied or otherwise particularly adapted to specificenvironments, manufacturing specifications, design parameters or otheroperating requirements without departing from the general principles ofthe same.

Although the invention has been described herein with reference tocertain preferred embodiments, one skilled in the art will readilyappreciate that other applications may be substituted for those setforth herein without departing from the spirit and scope of the presentinvention. Accordingly, the invention should only be limited by theClaims included below.

The invention claimed is:
 1. A method for generating infrared lightcomprising the steps of: providing a solid state source, comprising: afilm of oxide particles comprising: an average particle size of lessthan ten micrometers; and gaps between said oxide particles comprisingan average gap width of less than ten micrometers; a heating elementembedded in said solid state source; applying a pulsed current to saidheating element to heat said heating element; heating said film of oxideparticles to at least seven hundred degrees using thermal conductionfrom said heating element; and said film of oxide particles emitting theinfrared light, the infrared light comprising photons in the range of1.1 to 20 micrometers.
 2. The method of claim 1, said step of heatingfurther comprising the step of: thermally conducting heat from saidheating element through an intervening layer to said film of oxideparticles.
 3. The method of claim 2, further comprising the step of:protecting an emission side surface of said film of oxide particles fromoxidation using a first layer comprising silicon nitride.
 4. The methodof claim 2, further comprising the step of: heating said heating elementto at least seven hundred degrees centigrade and cooling said heatingelement to under two hundred degrees centigrade at least five times persecond and less than thirty times per second over a time period of atleast a minute.
 5. The method of claim 4, said step of emitting furthercomprising the step of: generating a distribution of photon energieswith a peak intensity in a range of 2.0 to 6.0 micrometers, wherein saidoxide particles comprise molybdenum oxide particles.
 6. The method ofclaim 4, said step of emitting further comprising: generating adistribution of photon energies with a peak intensity in a range of 3.0to 10.0 micrometers, wherein said oxide particles comprise a ceramic. 7.The method of claim 4, said step of emitting further comprising:generating a distribution of photon energies with a peak intensity in arange of 3.9 to 10.0 micrometers, wherein said oxide particles comprisezinc oxide particles.
 8. The method of claim 7, further comprising thestep of: transmitting a portion of the infrared light through at leasteighty percent of a thickness of said film of oxide particles.
 9. Themethod of claim 7, said step of emitting further comprising the step of:emitting photons from an internal volume of said film of oxideparticles; and transmitting at least fifty percent of the photons to anouter surface of said film of oxide particles.
 10. The method of claim1, said step of applying a pulsed current to said heating elementfurther comprising the step of: isolating the current to said heatingelement through use of: a first deposited dielectric film on a firstside of said heating element and a second deposited dielectric film on asecond side of said heating element.
 11. An apparatus for providinginfrared light, comprising: a solid state source, comprising: a film ofoxide particles comprising: an average particle size of less than tenmicrometers; and gaps between said oxide particles comprising an averagewidth of less than ten micrometers; a heating element embedded in saidsolid state source, wherein, during use, heat from said heating elementheats said film of oxide particles to at least seven hundred degrees viathermal conduction, resultant in the oxide particles emitting theinfrared light, the infrared light comprising photons in the range of1.1 to 20 micrometers.
 12. The apparatus of claim 11, said heatingelement further comprising: a connection for connecting to an duty cycledriver, wherein the pulsed current heats said heating element duringuse.
 13. The apparatus of claim 12, said film of oxide particles furthercomprising: a deposited filler in the gaps between said oxide particles.14. The apparatus of claim 12, said film of oxide particles formedthrough deposition.
 15. The apparatus of claim 14, further comprising atleast one of boron oxide and silicon oxide interspersed between saidoxide particles.
 16. The apparatus of claim 11, further comprising: anon-air material filling at least half of a volume occupied by the gapsbetween the oxide particles.
 17. The apparatus of claim 16, wherein atleast ninety percent of said oxide particles comprises a form of zincoxide.
 18. The apparatus of claim 12, said heating element furthercomprising: a deposited electrically conductive metal oxide film. 19.The apparatus of claim 18, further comprising: at least one electricalinsulating layer between said deposited electrically conductive metaloxide film and said film of oxide particles.
 20. The apparatus of claim18, said metal oxide film further comprising: a zinc oxide deposit.